Unexpected actual parameter type for type – How to solve this Elasticsearch error

Opster Team

July-20, Version: 1.7-8.0

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This guide will help you check for common problems that cause the log ” Unexpected actual parameter type for type ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: parser and plugin.

Log Context

Log “Unexpected actual parameter type [{}] for type [{}]”classname  is ExpressionBuilder.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 final DataType sourceType;
 try {
 sourceType = DataTypes.fromJava(param.value);
 } catch (QlIllegalArgumentException ex) {
 throw new ParsingException(ex; source; "Unexpected actual parameter type [{}] for type [{}]"; param.value.getClass().getName();
 if (sourceType == dataType) {
 // no conversion is required if the value is already have correct type
 return new Literal(source; param.value; dataType);


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